Field Service Bulletin

FSB.0009 Ver 1.0

June 8, 2021

CNG Gen 3 RM Refuse Fuel System PRD Retrofits
Affected
Vehicles

Refuse vehicles equipped with Hexagon Agility® the following Gen 3 Roof Mount CNG fuel
systems:
a) 20435000 and 20435000-WM
d) 20535000 and 20535000-WM
b) 20436000 and 20436000-WM
e) 20536000 and 20536000-WM
c) 20437000 and 20437000-WM
f) 20537000 and 20537000-WM

Introduction
Agility Fuel Solutions LLC, a subsidiary of Hexagon Agility Inc. (Hexagon Agility®), has determined that
certain OMB pressure relief devices (PRDs) have been observed to crack or fracture. The PRD failure
mode—seen to occur at or near first fill—can result in a sudden release of the high-pressure gas
contained in the CNG fuel system to the atmosphere.
Hexagon Agility® has created a PRD retrofit kit, p/n 20535030, to correct this issue on Hexagon Agility®
Gen 3 roof mount (RM) refuse fuel systems.
This bulletin also provides instructions for authorized Hexagon Agility® personnel to install PRD retrofit
kit, p/n 20535030.
Warning Statements Used in this Bulletin
WARNING indicates a hazardous situation which, if not avoided, could result in
death or serious injury.
NOTICE is used to address practices not related to physical injury, such as best
practices or tips to help an operation or procedure go smoothly and prevent
equipment damage.
CRITICAL CHARACTERISTIC – Product feature directly affects:
 Safety of vehicle users, people nearby and maintenance personnel, or
 Regulatory compliance.
MANUFACTURING CHARACTERISTIC
 A product feature solely used to improve manufacturability or maintain process
control.
 A process parameter or step that has a significant effect on achieving a Critical
Characteristic or Significant Characteristic, or maintaining material identification/
traceability.

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Required Tools and Materials
Item
Safety glasses
Scaffolding
Fall restraints
Combination and socket wrenches
Torque wrench
Crow foot wrenches
Swagelok® Snoop® leak detection fluid
Battery powered impact w/ 7/32-in hex bit
Permanent marker
Torque Seal marker
Shop rags

Purpose
Eye protection
Safe access to fuel system
Safe access to fuel system
Remove and install fuel system fittings, fasteners, and components
Accurately tighten fuel system fittings, fasteners, and components
Use with torque wrench
Perform leak test
Remove and install fuel system cover
Mark compression fittings
Indicate fittings and fasteners are tightened to specifications
Clean fuel system tubing before and after retrofit

Warranty Information

This procedure and the retrofit kits are covered under the provisions of the fuel system warranty.

Prior to Beginning Work
1. Verify contents of Retrofit Kit, Beta Valve PRD, Gen 3 RM, Hexagon Agility® p/n 20535030 is present in the
correct quantities. FIGURE 1
Item

Part Number

1
2
3
4
5
6
7
8*

10200063
10200236
10240625
10306997
20437408
20535027
20535028
10200250

Description

QTY

Fitting, Connector, Male
Fitting, Adapter, Male
Fitting, Straight, Male
PRD, Emer, Remote
Tube, Formed, Live PRD, 3/8-in x .049-in, Valve to Manifold
Tube Subassembly, 20535425, PRD to Vent
Tube Subassembly, 20535426, PRD to Vent
Nut and Ferrule Set - NOTE: use QTY: 2 with each (5)

*Not shown

NOTE:
4

2

2
2
2
2
2
1
1
4

3

 Items 1, 3, 4, and 6 comprise
“left PRD vent tube assembly”
 Items 1, 3, 4, and 7 comprise
“right PRD vent tube assembly”

7
6
4

1

2
3

1

5

FIGURE 1. Parts List — Retrofit Kit, Beta Valve PRD, Gen 3 RM, Hexagon Agility® p/n 20535030
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2. If any parts are missing or unusable, contact Hexagon Agility® Customer Care and Technical Services (CCTS)
for replacement.

Do not remove components from original packaging until necessary. Any
components to be reinstalled must be thoroughly cleaned, inspected and
stored in a satisfactory manner until reinstallation.
Wear approved personal protective equipment (PPE) including safety
glasses.

Secure Vehicle
Set emergency brake.
Place wheel chocks under vehicle tires.
Use approved scaffolding and fall restraints.

Defuel Vehicle
Refer to defueling sections of ENP-516, Truck and Tractor CNG Fuel System
Operation, Maintenance & Inspection Manual.

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Install PRD Retrofit Kit, p/n 20535030
1. Use a battery powered impact tool and a 7/32-in hex bit to remove fuel system cover valve fasteners and set
aside in a safe place. FIGURE 2

2

1
3

FIGURE 2. RM fuel system cover components
1 cover

2 doors

3 valve end panel

2. Open doors. FIGURE 2
3. Remove valve end panel to expose cylinder valve end plumbing. Refer to OEM instructions. FIGURE 2

NEVER put a wrench on a fuel system fitting without first confirming the
system has been depressurized.

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4. Use a pair of 11/16-in wrenches to remove (3) left PRD vent tube from (5) left PRD. FIGURE 3
NOTE: Left valve details shown;
mirrors right valve.

4

3
6

1

5

4

8
2

7

6

4

3

1

5

FIGURE 3. Left fuel system valve end plumbing components
1 left cylinder valve
4 left live PRD tube
2 cylinder
5 left PRD
3 left PRD vent tube
6 tube clamp
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7 structure
8 left manifold

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5. Use a pair of 11/16-in wrenches to remove (4) left live PRD tube from (1) left cylinder valve and (8) left
manifold. FIGURE 3
6. Use a 7/16-in socket and a 7/16-in wrench to remove fasteners securing (6) tube clamp and (3) left PRD vent
tube to (7) structure and set fasteners and clamp aside for reuse. FIGURE 3

Reuse, recycle, or discard tube assemblies removed according to
authority having jurisdiction (AHJ) and/or organizational guidelines.
7. Use a 7/8-in wrench to remove (5) left PRD from (1) left cylinder valve. FIGURE 3

Reuse, recycle, or discard PRDs according AHJ and/or organizational
guidelines.
8. Use a 9/16-in wrench to install (2) male adapter fitting, p/n 10200236, from retrofit kit on left cylinder valve
(not shown). FIGURE 4

Torque male adapter fitting to 26 ft-lbs (35.3 Nm).

3

1

2

FIGURE 4. Left PRD vent tube assembly and male tube adapter fitting
1 left PRD vent tube assembly
2 male adapter fitting, p/n 10200236

3 male connector fitting, p/n 10240625

9. Use a 11/16-in wrench to install male connector fitting, p/n 10200063, of (1) left PRD vent tube assembly
while using a 5/8-in wrench to hold (2) male tube adapter, p/n 10200236. FIGURE 4 and FIGURE 5

Tighten connector fitting nut per Appendix A: WI.0441 Tightening of Tube Fittings
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6
1

4

2

5

4

3

6

1